On Sun, Aug 11, 2019 at 10:12:47AM +0200, Christoph Hellwig wrote: > The kvmppc ultravisor code wants a device private memory pool that is > system wide and not attached to a device. Instead of faking up one > provide a low-level memremap_pages for it. Note that this function is > not exported, and doesn't have a cleanup routine associated with it to > discourage use from more driver like users. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > include/linux/memremap.h | 1 + > mm/memremap.c | 74 ++++++++++++++++++++++++---------------- > 2 files changed, 45 insertions(+), 30 deletions(-) > > diff --git a/include/linux/memremap.h b/include/linux/memremap.h > index 8f0013e18e14..eac23e88a94a 100644 > +++ b/include/linux/memremap.h > @@ -123,6 +123,7 @@ static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) > } > > #ifdef CONFIG_ZONE_DEVICE > +void *memremap_pages(struct dev_pagemap *pgmap, int nid); > void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap); > void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap); > struct dev_pagemap *get_dev_pagemap(unsigned long pfn, > diff --git a/mm/memremap.c b/mm/memremap.c > index 09a087ca30ff..7b7575330db4 100644 > +++ b/mm/memremap.c > @@ -137,27 +137,12 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref) > complete(&pgmap->done); > } > > -/** > - * devm_memremap_pages - remap and provide memmap backing for the given resource > - * @dev: hosting device for @res > - * @pgmap: pointer to a struct dev_pagemap > - * > - * Notes: > - * 1/ At a minimum the res and type members of @pgmap must be initialized > - * by the caller before passing it to this function > - * > - * 2/ The altmap field may optionally be initialized, in which case > - * PGMAP_ALTMAP_VALID must be set in pgmap->flags. > - * > - * 3/ The ref field may optionally be provided, in which pgmap->ref must be > - * 'live' on entry and will be killed and reaped at > - * devm_memremap_pages_release() time, or if this routine fails. > - * > - * 4/ res is expected to be a host memory range that could feasibly be > - * treated as a "System RAM" range, i.e. not a device mmio range, but > - * this is not enforced. > +/* > + * This version is not intended for system resources only, and there is no Was 'is not' what was intended here? I'm having a hard time reading this. Jason
